Such a voltage transformer is disclosed in Swiss Pat. No. 627,853. This voltage transformer comprises a cylindrical test electrode and an associated counter electrode. At least one of the two electrodes has at least two concentric radially projecting rings defining at least one cylindrical socket therebetween and the other of the electrodes has a ring which is disposed in each socket formed in the other electrode. The test and counter electrodes are supported on a disc-shaped support element. The force of the insulating gas located in the interior of the metal encapsulation acts on the support element, which is capable, if required, of bending slightly. Such bending causes the counter electrodes to be displaced toward and away from each other. A similar displacement of the test and counter electrodes can also be caused by shrinkage of certain insulating elements due to thermal or hygroscopic causes. These displacements of the electrodes with respect to one another cause the gas path between them, and thus the capacitance determining the accuracy of a test, to be changed. Such a voltage transformer, therefore, does not always produce the precision required in high-accuracy classes of systems.